1. Field of the Invention
The present invention relates to a lateral pipe lining material for lining a lateral pipe that branches off from a main pipe, and to a lateral pipe lining method using the lateral pipe lining material.
2. Description of the Prior Art
A pipe lining method is known in which, when an underground sewer pipe or other pipe has degraded over time, the pipe is not extracted from the ground, but, instead, a lining is applied to an inner peripheral surface of the pipe to repair the pipe. In this pipe lining method, a tubular pipe lining material comprised of a flexible tubular resin-absorbing material is used, which is impregnated with a curable resin and whose outer peripheral surface is covered with a highly airtight film. The pipe lining material is evertedly inserted into the pipe by fluid pressure and pressed against the inner peripheral surface of the pipe. In this state, the pipe lining material is heated to cure the curable resin impregnated therein, thereby lining the inner peripheral surface of the pipe.
The above-described method can also be used for lateral pipes that branch off from a main pipe. Such a lateral pipe lining method is disclosed in, e.g., Japanese Laid-open Patent Application No. 1994-270253. In this method, a work robot is used to bring a brim formed on one end of a lateral pipe lining material into close contact with a peripheral edge of a lateral pipe opening of the main pipe. The lateral pipe lining material is then evertedly inserted into the lateral pipe. The curable resin in the lateral pipe lining material is cured and the lateral pipe is lined while the evertedly inserted lateral pipe lining material is pressed against an inner peripheral surface of the lateral pipe. The resin impregnated into the lateral pipe lining material flows into a gap between a surface of the brim on an opening side and an inner surface of the main pipe. This allows the main pipe to be integrally joined with the lateral pipe lining material.
The lateral pipe is usually lined before the main pipe is lined. However, the lateral pipe may also be lined after the main pipe is lined (also referred to as “after lining”).
However, a problem arises in that, when water seeps from the ground into a portion that is to be lined, the water will seep into a gap between a lateral pipe opening of a main pipe and a brim of a lateral pipe lining material, and it will become impossible to cure a thermosetting resin. In addition, a problem arises in that, when an adhesive composed of thermosetting resin is applied to a surface of the brim on a lateral pipe opening side, the resin will become fluid and flow away from the surface of the brim due to heat generated when the resin is cured.
It is therefore an object of the present invention to provide a pipe lining material and a lateral pipe lining method that can be used to securely line a lateral pipe even at a work site where water will seep in from the ground.